Puppet-valve



(N o Model.)

J. HEMPI-IILL. PuppetvValve.

N0. 238,685. Patented' March 8, |881.

N. PETERS. FHOTO-LlTHOGRAPNER. WASHINGTON, D t:A

UNTTED STATES PATENT EETEE.

PUPPET-VALVE.

,SPECIFICATION forming part of Letters Patent No. 238,685, dated March8, 1881.

Application led September 20, 1880.

To all whom t may concern Be it known that I, JAMES HEMPHILL, ofPittsburg, county ofAllegheny, State ot' Pennsylvania, have invented ordiscovered a new and useful Improvement in Puppet-Valves; and I dohereby declare the following to be a full, clear, concise, and exactdescription thereof, reference being had to the accompanying drawings,making apart of this specification, in whichlike letters indicating likeparts- Figure l is a sectional view of the steamcylinder of a verticalengine illustrative of the arrangement of the valves with referencethereto, as also of the construction of the valves themselves, the twoupper valves being shown in elevation and the two lower in section. Fig.2 is a sectional view, toasoinewhat larger scale, of one ot' thereceiving or steamsupply valves, and illustrating its arrangement withreference to a horizontal cylinder; and Fig. 3 is a top view of thevalve.

My present invention relates to certain improvementsin the old andwell-known balanced puppet-valve, whereby I am enabled to secure a moreperfect balanein g, greater compactness of construction, and amoreequable and uniform motion, as well as greater facility in the insertingand removing of the valve in repairs, or for other purposes.

lo this end l make the body of the valve, between its seats, largeenough for the making therein of one, two,or more steamports, whichextend from end to end ot' the Valve, and I extend the steam-supplychamber around, or almost entirely around, the body of the valve,between its end seats, and also so construct the other parts of thevalve-chamber that, the valve being seated at its lower end directly onthe cylinder-wall, it shall, when u useated, admit steam through bothseats or ports, as a result ot' which the valve is balanced bysteamlpressure, and the ports through the valve give additional room forthe passage of steam.

The cylinder of a vertical engine is represented at A, and A is itspiston, and A2 the pistonstem. The steam-supply pipe may be connected atBv and the exhaust-pipe at B. The passages b lead tothe valve-chambersBZ, and on the opposite side like passages, b', lead from theexhaust-valve chambers B3. In the (No model.)

steam-supply valve-chambers B2, I arrange the valves V, and I will tirstdescribe the construction and arrangement of these valves. Each valve ismade with two seating-faces, a a', which, when the valve is seated, restand make close joints on the seats s s. The upper seat (and by upper Imean the one most distant from the cylinder) has a slightly lessdiameter than the lower, and at least so much or such length ot' thebody ot' the valve between its seating-faces as is intended in themotion of the valve to play through the upper seat is made slightly lessin diameter than the seat itself, so that when the valve is unseatedsteam may not only pass under the valve through the port c and into thecylinder, but may also, and at the same instant ottime, pass between thebody of the valve and the upper valve-seat into that part, d, of thevalve-chamber which is above the valve, and thereby apply steampressureto both ends of the valve simultaneously, and so practically balance it;and also such steam, while thus acting in its progress as a balancingagent, may also pass along through the port or ports` e, which I makelengthwise through the valve, and so, passing through the port c,enterthe cylinder. 1n order to get a good steam-supply and keep the Valvebalanced laterally as well as longitudinally, I carry the passage b wellaround the valve at b2; and in order that the valve may be properly'guided at both ends I add guiding-ribs t', or equivalent deviceperforming a like function, and in any desired number, around both endsof the valve. It will now be seen that when the valve is seated therewill be a slight preponderance ot' downward or seating pressure, andwhen unseated the preponderance will be slightly the other way. Hencethe positive motions ot unseating and seating, which are com municated.through any suitable means to the valve-stems c, are always against thepressure, which is a desirable feature in valves of this class. It isalso an important feature that on the opening of the valve theapplication of a balancing-pressure to the upper end is as instantaneousas the application of luidpressure below the Valve, and

also that the ports through the valve operate as steam-supply ports tothe cylinder.

I am aware that holes through puppet-valves IOO are old; but so far as Iam aware they have been only organized heretofore so as to convey thebalancing steam-pressure from beneath the valve to the balancing chamberor pocket above, there being in such construction, as heretoforepracticed, a packing around the valve, which prevented steam from thepocket above the valve from passing into the cylinder. In suchconstruction the practical difticulty is met with that the rst pressureof steam, when the valve is opened, is 011 the lower end of the valve,and this causes the valve to jump, as it is called.

My improved construction differs from this, among other respects,insupplying steam both above and below the valve simultaneously, so as tobalance 'it at once, and so prevent jumping; and also in dispensing withthe packing, and so organizing the valve that the holes or ports throughthe valve operate as steam-supply ports on the receiving-slide andexhaustports on the other side without at all impairing or materiallylessening the balancing effect desired. Also, as a result of supplyingsteam both above and below the valve from a steam-space, b2, between thevalve-seats, Iam enabled to set the valve directly on the port c, madein the wall or shell of the cylinder. As the lower end of this valve isthe larger, I make provision for inserting it in and removing it fromits chamber without making the body of the valve-chamber in separateparts, and this I do by the use of a bushing, a', the exterior diameterot' which is at least equal to the exterior diameter of the largest partof the valve. The interior wall ot' this bushing above the valve-seat isprovided with ribs, as shown, so as to act as a guide to the upper endof the valve, and also leavea steam-space between the upper valve andthe bushing for the free ow of steam past the valve-head Vwhen the valveis unseated; but such guiding-ribs may be made on the valve-head itselfand play against the cylindrical cavity of the bushing. The uppervalve-seat is made in this bushing, and the latter is seated and held inplace by a bevel-seat and shoulder, as at Then the valve and bushing canbe putin and removed together.

The exhaust-valves V are of the same construction and operation, exceptthat the upper end of the valve is slightly thelarger, and the uppervalve-seat has a little the greater diameter, so that no bushing isneeded, land also so that when the valve is seated steam-pressure,acting through the ports c, shall, in the chamber or pocket cl, balancethe valve, with a slight preponderance of downward effect.4 Also, whenthe valve is unseated, steam passing through the holes or ports e willmaintain a practical and substantial balance, and will also exhaustthrough said ports and through the partiallyopen port of the uppervalveseat, as well as through the fully-open port of the lower seat.

While I'have described my improved valve as specially adapted tovertical engines, I do not limit myself to its use therewith, as it maybe advantageously used with horizontal cylinders as well.

I claim herein as my invention- 1. In combination with a steam-port, c,made directly in the wall, body, or shell ot' a stealncylinder, adouble-balanced puppet-valve seated directly thereon, without anyintervening pocket, and a steam-port opening directly from between thevalve-seatingfaces simultaneously through both valve-seats on theuuseating of the valve, substantially as set forth.

2. The double-balanced puppet-valve V, larger at the lower than at theupper end, in combination with a bush, sv, adapted to furnish a seat forthe valve and guide the same in its motion to and from its seat bysuitable interposed guides, substantially as set forth.

In testimony whereof I have hereunto set my hand.

JAMES HEMPHILL.

Witnesses:

R. H. WHITTLESEY, GEORGE H. CHRISTY.

